Manholes provide access to underground networks. For example, in urban areas underground networks for utility and sewage systems are generally accessible via manholes. Both underground personnel and working materials enter and exit the underground networks via the manholes. Devices for lowering and raising working materials are utilized for assisting underground workers transport necessary equipment into and out of the manholes. These hoisting devices can be bulky and cumbersome and get in the way of underground workers who wish to enter or exit a manhole having a hoisting device over it.
Conventional fixed manhole hoisting devices are not only cumbersome, but they can only raise and lower objects vertically and are not capable of horizontally maneuvering hoisted objects. Once an object is raised out of a manhole, workers must maneuver the object away from the manhole and over a surface area adjacent to the manhole where the object can be lowered onto the adjacent surface area.
The inventor is not presently aware of hoisting devices that are designed to be secured to a conventional manhole guardrail. It would thus be desirable to provide a hoisting apparatus for a manhole which is compact, lightweight, capable of maneuvering objects horizontally, and formed from a minimum number of non-complex parts.